Psychedelics, including psilocybin, lysergic acid diethylamide (LSD) and related psychoplastogens, have re-emerged as powerful modulators of brain function with therapeutic potential across a broad range of neuropsychiatric disorders. Although prevailing mechanistic frameworks emphasize neuronal serotonin 2 A receptor (5-HT2AR)-mediated signaling, accumulating evidence suggests that astrocytes-once regarded primarily as passive support cells-may play active and potentially central roles in shaping psychedelic-induced brain states. Astrocytes are uniquely positioned to integrate neuromodulatory signals, regulate synaptic transmission, coordinate metabolic support, and orchestrate neuroimmune responses. Here, we hypothesize that astrocytes function as critical integrative nodes translating psychedelic-induced receptor activation into circuit-level plasticity and lasting behavioral change. We synthesize emerging evidence on astrocytic calcium signaling, gliotransmission, metabolic coupling, neurovascular regulation, and immune gating in the context of psychedelic action. Based on these observations, we introduce the hypothesis of a neuro-glial ensemble framework in which neuron-astrocyte interactions may constitute a minimal functional unit contributing to psychedelic-induced network reorganization. This systems-level perspective offers a testable mechanistic hypothesis linking receptor pharmacology to large-scale brain dynamics and clinical outcomes. We conclude by outlining key predictions of this hypothesis and proposing experimental strategies to rigorously test them.
Psychedelic Science